Quaternary ammonium compounds of basic esters of 2-aryl-2-(1-hydroxycyclopentyl) ethanoic acids



containing 1 to 6 carbon atoms.

United States Patent QUATERNARY AMMONIUM COMPOUNDS or BASIC ESTERS OF -2-ARYL-2-(1-HYDROXY- H CYCLOPENTYL) ETHANOIC ACIDS Gino R. Treves, New York, N..,-assignorjt o Schiefielin & C0., New York, N. Y., a corporation of New York No Drawing. Application April 18, 195 1, Serial No. 221,751

14 Claims. Cl. 260-473 This invention relates to compounds having antispasmodic activity, and particularly to quaternary ainmonium compounds of dialkyl amino alkyl esters of 2- aryl-2-( l-hydroxycyclopentyl)ethanoic acids. The aryl radical is chosen from the groupc'onsisting of phenyl and alkoxyphenyl while the hydroxycyclopentyl radical mayor may not be substitu'tedby an alkylgro'up. Re lated compounds are described in cop'ending application Serial No. 94,534, filed May 20, 1949, now Patent 2,554,511, issued May 29, 1951, of which the present application is a continuation-in-part.

One of the best known antispasm'odicagents isatropine, the use of which, however,is limited because of the unwanted side reactions which characterize it. The present compounds possess advantageousantispasmodic properties, particularly anticholinergic activity, to a degree comparable to, or better than, that of atropine, and they possess anticholinergic activity exceeding most commercial preparations. For purposes of Classification'the .compounds may be described as having an atropinelike action, that is, they have neurotropic activity.

The compounds may be represented generally by the formula:

A(|3HCOO(OHz);.M

in which Ais a group 'seleetedfrom the class consisting of hydroxycyclopentyl and alkyl-substituted hydroxycyclopentyl groups, n is a whole number varying fro m 1 to 6, M is a quaternary ammonium salt moiety, and-B is a radical selected from the class consisting of ;ph'enyl and alkoxyphenyl radicals, the alkyl and alkoxy groups each A more particular way of representing theeoiiipounds is:

where A and B are the same as before, R is a bivalent radical containing only carbon and hydrogen and having 1 to 6 carbon atoms and being derived from an aliphatic hydrocarbon by removal of a hydrogen atom from each of two terminal carbon atoms, R is an alkyl group, R is a univalent radical containing only carbon and hydrogen and being selected from the group consisting of alkyl, alkenyl, and aralkyl radicals, and X is an anionic moiety of an organic ester. Preferred compounds may be represented by the formula:

in which A, n, and B are the same as before, R is an alkyl group preferably containing 1 to 6 carbon atoms, and X is a halogen radical. A specific example of the compounds is the methochloride of beta-(diethylamino)- 2,770,647 Patented Nov. 13,1956

'ice

i HzCH:

The compounds may be suitably prepared by reacting the free base (obtainable as described in the above-mention copending application) with an alkyl halide, aralkyl halide, or alkenyl halide. Preferably the halide containing agent is a bromide oran iodide; it may also be a chloride, although quaternary ammonium chloride compounds of the invention are preferably made by converting a quaternary ammonium bromide or iodide compound by means of a salt like silver chloride. Other agents for converting the free base to a quaternary ammonium salt are diakyl sulfate, aryl sulfonic acid. ester, etc. Specific examples 'ofquaternary ammonium salts of the dialkyl amino alkyl esters of the above described substituted ethanoic acids are the methiodide, methobromide, methochloride, ethiodide, ethobromide, benzobromide (benzyl bromide), propeniodide (propenyl iodide), diethyl sulfate, etc.

The following examplesmay illustrate the preparation ofthe compounds:

Example 1 Approximately 5 cc. of a solution of sodium bicarbonate were shaken with 1 gram of thehydrochloride of beta-(dimethylamino)ethyl ester of 2-phenyl-2-(1-hydroxycyclopentyl)ethanoic acid (prepared as described in said copending application) and with 11 cc. of anhydrous ether. Theether solution was separated and the bicarbonate solution extracted with more ether. The 'coi'nbinedether extracts were dried over anhydrous :potassium carbonate and the ether drivenoff on-the steam bath. The residue was dissolved in 5 cc. ofabsolute alcohol and anexcess of methyl iodide (1 cc.)-added and left' at room" temperature for a fewhours. The excess methyl iodide and alcohol were driven off on :the steam "bathunder reduced pressure. The residue was dissolved in a mixture of ethyl acetate, ethanol, and etherfrom whichit crystallized. It was the methiodide of beta- (dimethylamino)ethyl ester of 2-phenyl-2-(l-hydroxycyclopentyDethanoic' acid, melting at -131 C.

By using the method of Example 1,-the followingwadditiorial quaternary ammonium compounds were prepared, in each case the starting compound being the corresponding free base or the acid addition salt of such free base. The latter salt is readily converted to the free base by treatment with an alkali.

Example 2 Methiodide of beta-(dimethylamino)ethyl ester of 2- phenyl-2-( l-hydroxycyclopentyl)ethanoic acid, which was crystallized from an ethyl acetate-ethanol mixture and recrystallized from ethanol and ether. It melted at 142- 143 C.

Example 3 Methiodide of beta-(dimethylamino)ethyl ester of 2- (4-methoxyphenyl) 2 (l-hydroxycyclopentyl)ethanoic acid, crystallized from. a mixture of ethyl acetate and ethanol and melting at 129-131 C.

Example 4 Ethiodide of beta-(dimethylamino)ethyl ester of 2- phenyl-2-(l-hydroxycyclopentyl)ethanoic acid, crystallized from absolute ethanol and melting at 136-137" C.

To prepare this compound ethyl iodide was used in place of the methyl iodide of Example 1.

Example 5 Example 6 One gram of the compound of Example 2 was refluxed in 15 cc. of methanol for 1 hour with .35 gm. of silver chloride. The mixture was then cooled and filtered. The solvent was driven off and the residue crystallized from a mixture of ethanol and ether. I It was the methochloride of beta-(diethylamino) ethyl ester of 2-phenyl- 2-( l-hydroxycyclopentyl)ethanoic acid, melting at 161- 163 C.

When tested according to the Magnus technique on isolated strips of rabbit ileum previously subjected to the action of acetylcholine to induce spasm, the above described compounds displayed a high degree of anticholinergic activity of the order of magnitude of atropine. The compound of Example 6 displayed anticholinergic activity greater than that of atropine.

In the light of the foregoing description, the follow ing is claimed:

1. The compound:

ACHCOO(CH:)M

in which A is a group selected from the class consisting of l-hydroxycyclopentyl and alkyl-substituted l-hydroxycyclopentyl groups, n is a whole number varying from 1 to 6, M is a quaternary ammonium salt moiety, and B is a radical selected from the class consisting of phenyl and alkoxyphenyl radicals, said alkyl and alkoxy groups each containing 1 to 6 carbon atoms.

2. The compound:

in which A is a member of the group consisting of l-hydroxycyclopentyl and alkyl-substituted l-hydroxy-cyclopentyl groups, n is a whole number varying from 1 to 6, R is an alkyl group, X is a halogen radical selected from the group consisting of chlorine, bromine, and iodine, and B is a member of the group consisting of phenyl and alkoxyphenyl groups, said alkyl and alkoxy groups each containing 1 to 6 carbon atoms.

3. The compound of claim 2 in which A is a 1-hydroxycyclopentyl group and B is a phenyl group.

4. The compound of claim 2 in which A is a 1-hydroxy cyclopentyl group and B is an alkoxyphenyl group.

-5. The compound of claim 2 in which A is an-alkylsubstituted l-hydroxycyclopentyl group and B is a phenyl group.

6. The compound of claim 2 in which A is an alkylsubstituted l-hydroxycyclopentyl group and B is an alkoxyphenyl group.

7. The quaternary ammonium compound:

in which A is a group selected from the class consisting of l-hydroxycyclopentyl and alkyl-substituted l-hydroxycyclopentyl groups, R is a bivalent radical containing only carbon and hydrogen and having 1 to 6 carbon atoms and being derived from an aliphatic hydrocarbon by removal of a hydrogen atom from each of two terminal carbon atoms, R is an alkyl group, R is a univalent radical containing only carbon and hydrogen and being selected from the group consisting of alkyl, alkenyl, and aralkyl radicals, X is an anionic moiety selected from the group consisting of a halogen radical, ArSOr, and RSOr where Ar is aryl and R is alkyl, said halogen radical being a member of the group consisting of Cl" Br", and I, and B is a radical selected from the class consisting of phenyl and alkoxyphenyl radicals, said alkyl and alkoxy groups each containing 1 to 6 carbon atoms.

8. A compound according to claim 7 in which R is an alkyl radical having 1 to 6 carbon atoms.

9. A compound according to claim 7 in which R is an alkyl radical having 1 to 6 carbon atoms and X is a halogen radical selected from the group consisting of Cl, Br, and I.

10. A compound according to claim 7 in which R is an aralkyl'radical.

11. A compound according to claim 7 in which R is an alkenyl radical.

12. The methobromide of beta-(diethylamino)ethyl ester of 2-phenyl-2-(l-hydroxycyclopentyl)ethanoic acid.

13. The methoiodide of beta(diethylamino)ethyl ester of 2-phenyl-2-( l-hydroxycyclopentyl)ethanoic acid.

14. The methochloride of beta-(diethylamino)ethyl ester of 2-phenyl-2-(l-hydroxycyclopentyl)ethanoic acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,375,138 Salvin et a1. May 1, 1945 2,399,736 Holmes et a1. May 7, 1946 2,428,978 Martin et a1. Oct. 14, 1947 2,554,511 Treeves May 29, 1951 2,589,224 Burtnes Mar. 18, 1952 OTHER REFERENCES Berger: Medicinal Chemistry, 1951, p. 434. 

1. THE COMPOUND: 